Yeah, they get it crazy cheap. I looked into buying from US websites but on top of horrible shipping costs our taxman will absolutely rape you if you try to import tobacco. If you have any friends over there the most they can send you for a "special occasion" is 50 grammes (2 ounces).
Like you, I started with Otc baccy but quickly moved on to bulk and tins, they are SO much better. My "all day" smoke is a 50:50 mix of Balkan + Cherry & Vanilla. Then in the evenings I'll break out the virginias, englishes etc... Variety is the spice of life!